25 
be made known. It is to establish a fact of this sort that these 
notes have been written. I will, however, if you will permit me 
refresh your memory as to the points which want clearing up. 
The Mendip Hills, as you will see on looking at the map, run in a 
direction nearly east and west. Thestructureisan anticlinal one, i.¢., 
the beds incline on each side against a central ridge, of Old Red 
Sandstone ; in other words they dip away in opposite directions 
from the centre, so that we have the Mountain Limestone beds on 
the south of the range dipping southwards, and those on the 
north dipping northwards ; and not only so, but if we follow 
these beds northwards we find them gradually dipping at an in- 
creased angle until they are actually seen perpendicular, and then 
_ dipping southwards again, before they finally turn right over, 
and what was originally the floor when in their first horizontal 
position now becomes the ceiling. I said in their “ first 
horizontal position,” for that these beds were originally flat, 
and that some irresistible force must have moved them from 
their original position and tumbled them about, as we find 
them in the Nettlebridge Valley, is evident. How that force 
originated, and what was its action, has hitherto been, and 
still is, the problem to solve. Whether it was accomplished 
all at once by some mighty convulsion of Nature, which hurled 
the Limestone mass at Vobster (some 1,150 yards in length 
and 300 yards in width) a distance of 1,300 yards, or about 
three-quarters of a mile, from the nearest Limestone beds 
south of it; or whether it was a gradual and slow process of 
upheaval and squeezing together of beds to the southwards, 
and subsequent tilting up and inversion of the whole mass, 
is what we are trying to discover, and which it would have 
been worth a geologist’s life-time, whilst pacing along the 
corridors of Time, to have seen. If it happened in the 
- former way it would be called a catastrophe, or cataclysmic 
action, against which the learned of the present day set their 
faces. And yet even now we see a modification of extreme 
